KR20210062292A - Flexible display apparatus - Google Patents

Abstract

According to an embodiment of the present specification, a flexible display device comprises: a flexible substrate comprising an active region and an inactive region, wherein the inactive region includes a first region adjacent to the active region, a second region on which a pad is disposed, and a bending region between the first region and the second region. The bending region includes a first bending portion, a second bending portion and a third bending portion according to the radius of curvature. The radius of curvature of the first bending portion is larger than the radius of curvature of the third bending portion to reduce defects that occur during bezel bending.

Description

Flexible display device {FLEXIBLE DISPLAY APPARATUS}

The present invention relates to a flexible display device, and more particularly, to a flexible display device capable of bending a display panel.

As the information age enters, the field of display that visually expresses electrical information signals has rapidly developed, and in response to this, various display devices with excellent performance of thinner, lighter, and low power consumption (Display Apparatus) Is being developed.

Specific examples of such a display device include a Liquid Crystal Display Apparatus (LCD), an Organic Light Emitting Display Apparatus (OLED), and a Quantum Dot Display Apparatus.

The display device may include a display panel and a plurality of components for providing various functions. For example, one or more display driving circuits for controlling the display panel may be included in the display assembly. Examples of driving circuits include gate drivers, light emitting (source) drivers, power (VDD) routing, electrostatic discharge (ESD) circuits, multiplex (multiplex) circuits, data signal lines, cathode contacts, and other functional elements. Includes them. A plurality of peripheral circuits for providing various types of additional functions, for example, touch sensing or fingerprint identification functions, may be included in the display assembly. Some components may be disposed on the display panel itself, or may be disposed on areas adjacent to the display area, which are non-display areas and/or inactive areas or non-active areas.

When designing a display device, size and weight are important issues. Also, a high ratio of the size of the active area to the size of the inactive area, referred to as the screen-to-bezel ratio, may be one of the main characteristics. However, placing some of the aforementioned components in a display assembly may require a large inactive area, which may add up to a large portion of the display panel. The large inactive area tends to make the display panel large, which makes it difficult to integrate the display panel into the housing of the display device. A large inactive area may require large masking (eg, bezel rim, covering material, etc.) to cover a large portion of the display panel, and may be a problem that may hinder the aesthetics of the display device.

Some components may be disposed on a separate flexible printed circuit board (FPCB) and may be located on the backplane of the display panel. However, even with such a configuration, components essential for driving the display panel such as interfaces for connecting wires between the FPCB and the active area or driver ICs are still disposed in the inactive area, and thus, may be a limitation in reducing the size of the bezel.

The inventors of the present invention have recognized that in order to implement a narrow bezel in which the size of an inactive area is reduced, various technologies including a location of a wiring, a width of a wiring, and a signal transmission method are required. Accordingly, the inventors of the present invention have conducted various studies using the bending characteristics of a display device to which a flexible substrate is applied. Through various researches, a new structure and manufacturing method have been invented to minimize a non-display area, for example, an inactive area, which is not an active area in which an image is displayed.

For example, in order to make the display device smaller and lighter by lowering the ratio of the inactive region, the ratio of the active region may be increased by bending a portion of the display panel. This allows some inactive areas to be located behind the active areas of the display panel, so that masking or inactive areas that must be covered under the housing of the display device can be reduced or eliminated. The bending of the display panel can minimize the size of an inactive area that must be covered in the field of view, implement a narrow bezel or bezel-free display device, and provide a flexible display device capable of improving aesthetics.

There are problems that must be solved in order to implement a flexible display device, and these will be described below.

Various components may be disposed directly on the flexible substrate together with the pixels of the display panel. Using a thin substrate for flexibility of a flexible substrate may cause components to be vulnerable due to various mechanical and environmental stresses that may occur after fabrication and/or completion. For example, mechanical stress due to bending of the display panel may affect the reliability of the display device, and furthermore, failures may occur in components. For example, components of wirings such as high-potential voltage (VDD) wiring, low-potential voltage (VSS) wiring, and data signal lines, which are arranged in a bent area extending from the inactive area, form a flexible substrate. Deformation may occur during the bending process of bending. In addition, in the process of attaching a flexible printed circuit board (FPCB) or light emitting (source) driver to the flexible substrate after the bending process, or in the process of bonding a display panel manufactured to a display device after the attachment, Deformation of the radius of curvature (R) may occur in a specific area. Deformation of the radius of curvature may not withstand tensile stress and/or contraction stress applied to high-potential voltage wiring, low-potential voltage wiring, or data signal lines arranged in the corresponding region, and disconnection or partial cracking may occur. The bending area of the flexible substrate may be a bending area or a bending portion.

Accordingly, in order to protect the components from various stresses that may occur during bending, an organic protective layer may be formed on the bending portion. For example, an organic film, which is a micro coating layer (MCL), may be disposed on the components of the bending area. In the absence of the micro-coating layer, components on the bending area are exposed to the outside, which can lead to chemical deformation by exposure to physical impact, moisture, and oxygen, and tensile stress that increases the upper surface area of the bending area relatively increases at the top of the bending area. It can be strongly applied to the various wirings located. The disconnection and partial cracks due to this may cause a driving failure of the display panel. A micro-coating layer may be disposed to protect various wirings of the bent portion to absorb physical and/or chemical shocks that may be received from the outside. Tensile stress and shrinkage stress can be applied less by making the wires arranged in the bent part close to the neutral plane in the laminated structure including the substrate and the micro-coating layer. It can absorb stress and reduce defects.

Despite the application of the micro-coating layer, it was recognized that wirings such as data wiring, high-potential voltage wiring, and low-potential voltage wiring in the bending portion are continuously disconnected or damaged. For example, it has been recognized that there are cases in which wirings may be damaged due to impacts occurring during a bending process of folding a part of a flexible substrate, mounting on a display module in a process after bending, or during use by a user after mounting.

Therefore, implementing a light-weight and thin display device and reinforcing the rigidity of the wiring in the bending area without reinforcing additional equipment is a narrow bezel or bezel-free display device that can prevent disconnection or damage that may occur before and after the bending process. Can be implemented.

The display device according to the exemplary embodiment of the present specification includes an active area and an inactive area, and the inactive area includes a first area adjacent to the active area, a second area in which a pad is disposed, and between the first area and the second area. A flexible substrate including a bending area, the bending area includes a first bending point, a second bending point, and a third bending point according to a radius of curvature, and a radius of curvature R1 of the first bending point is a radius of curvature of the third bending point May be greater than R3.

A display device according to an exemplary embodiment of the present specification includes a substrate including a display area and a non-display area, an encapsulation layer disposed on a light emitting display device and a light emitting display device disposed in the display area, and disposed on at least a portion of the non-display area The polarizing layer and the cover window disposed on the encapsulation layer, and the non-display area include a bending area, the bending area includes a first wiring line and a second wiring line directed to the light emitting display device, and the first wiring line and the first wiring line The second wiring lines may overlap each other in the bending area and may have a connection portion to which the first wiring line and the second wiring line are electrically connected.

Details of other embodiments are included in the detailed description and drawings.

In the display device according to the exemplary embodiment of the present specification, by applying a flexible substrate, all or part of the inactive area, which is a non-display area of the display panel, is folded into a shape having a predetermined radius of curvature and disposed on the rear surface of the active area. A display device having a narrow bezel can be provided.

Therefore, the user of the display device can use a device with an aesthetically lit screen full on the front of the display device, and by using a compact module applied to a narrow bezel, the display device has an excellent grip and light weight for the user. Device can be provided.

In the display device according to the exemplary embodiment of the present specification, when the entire or part of the inactive area is folded into a shape having a constant radius of curvature so that the distance between the substrate and the substrate becomes a constant thickness, various wirings disposed on the bent substrate area A coating layer may be disposed on the component formation to protect the back components. The coating layer may reduce external impacts that may be received before/after the manufacturing process of the display panel and tensile stress and shrinkage stress that may be received by components on the flexible substrate during the bending process. Due to the coating layer, a more stable display device can be provided by preventing the component from being disconnected or broken, and an abnormality in the bending part of the product can be prevented even when an impact is applied to the display device due to a user's carelessness.

In the display device according to the exemplary embodiment of the present specification, notches may be formed in at least two corner portions of the display panel in order to fold all or part of the inactive area into a shape having a predetermined radius of curvature. A more stable display device can be provided by optimizing the repulsive force of the flexible substrate, which may be generated by bending a relatively small area due to the arrangement of the notches, and minimizing stress that may occur on the flexible substrate.

In the display device according to the exemplary embodiment of the present specification, a support layer may be added to the lower surfaces of the active area and the inactive area of the flexible substrate. The support layer may protect light-emitting elements disposed in the display panel, circuits for driving, and other components from various twists and deformations that a flexible substrate made of a flexible material may receive during display panel manufacturing.

In the display device according to the exemplary embodiment of the present specification, wirings disposed in the bending area may be formed of a plurality of overlapping layers. If the wiring is formed in a double layer, a more robust wiring structure can be made against changes in the radius of curvature or external impact that may occur before/after the bending process. At the same time as the wiring structure becomes solid, even if one of the upper and lower wirings arranged in a double layer is disconnected, power and signal transmission through the remaining other wirings can be smoothly prevented to prevent display defects.

In the display device according to the exemplary embodiment of the present specification, wirings disposed in the bending area may be formed as a plurality of layers, and may be electrically contacted with each other by using an insulating layer. Since such a contact structure can reduce or optimize the area of the wiring subject to tensile stress and contraction stress generated for each section, disconnection or cracks occurring in the wiring can be reduced.

In the display device according to the exemplary embodiment of the present specification, a contact structure may be disposed to form a wide wiring width of a portion of the wiring disposed in the bending area in electrical contact with each other. The contact structure improves the contact force between the wirings, thereby preventing inter-line lifting of the contact area that may occur before/after the bending process.

In the display device according to the exemplary embodiment of the present specification, a plurality of contact structures arranged in the bending area may be continuously formed along the wiring to further improve the contact force between the wirings, and inter-line lifting in the contact area that may occur before/after the bending process. Can be prevented.

In the display device according to the exemplary embodiment of the present specification, wirings and contact structures arranged in a bending area are designed differently for each section, and the lengths of the wirings arranged in multiple layers according to a radius curvature (R) due to bending and the size of the contact structure You can do it differently. For example, the length of the wiring is shortened in the region where the bending radius of curvature R is the smallest, and the contact structure is arranged to be large, so that it is possible to withstand tensile/contraction stress caused by bending.

The display device according to the exemplary embodiment of the present specification may have a planar structure that does not interfere with each other between adjacent wirings in the bending area by having a structure disposed in the bending area have a circular plane or a rhombus plane.

The display device according to the exemplary embodiment of the present specification may have a planar structure in which adjacent wirings do not interfere with each other by staggering the arrangement of structures disposed in the bending area.

The effects of the present specification are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

Since the contents of the invention described in the problems to be solved above, the problem solving means, and effects do not specify essential features of the claims, the scope of the claims is not limited by the matters described in the contents of the invention.

1 is a diagram illustrating a plan view of a display panel according to an exemplary embodiment of the present specification.
FIG. 2 is a cross-sectional view taken along line II′ of FIG. 1.
3 is an enlarged cross-sectional view of a dotted line area III of FIG. 2.
4 is an enlarged view of a bending area in which the cut portion of FIG. 2 is bent.
FIG. 5 is an enlarged view of an area near the cut surface of the substrate in the portion BP1 of FIG. 4, and is a plan view of a wiring according to an exemplary embodiment of the present specification.
6 is an enlarged view of a region adjacent to the cut surface of the substrate in the portion BP2 of FIG. 4, and is a plan view of a wiring according to an exemplary embodiment of the present specification.
FIG. 7 is an enlarged view of an area near the cut surface of the substrate in the portion BP3 of FIG. 4, and is a plan view of a wiring according to an exemplary embodiment of the present specification.
8 is a cross-sectional view of a wiring taken along line III-III' of FIG. 6.
9 is a cross-sectional view of a wiring taken along line IV-IV' of FIG. 7.
10 is a cross-sectional view of a bending area according to an exemplary embodiment of the present specification.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. The same reference numerals refer to the same elements throughout the specification. In addition, in describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When'include','have', and'consist of' mentioned in the present specification are used, other parts may be added unless'only' is used. In the case of expressing the constituent elements in the singular, it includes the case of including the plural unless specifically stated otherwise.

In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description.

In the case of a description of the positional relationship, for example, if the positional relationship of two parts is described as'upper','upper of','lower of','next to','right' Or, unless'direct' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, when a temporal predecessor relationship is described as'after','following','after','before', etc.,'right' or'direct' It may also include cases that are not continuous unless this is used.

First, second, etc. are used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, the first component mentioned below may be a second component within the technical idea of the present invention.

In describing the constituent elements of the present specification, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, order, or number of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected or connected to that other component, but other components between each component It should be understood that "interposed" or that each component may be "connected", "coupled" or "connected" through other components.

In the present specification, the term "display device" refers to a liquid crystal module (LCM) including a display panel and a driver for driving the display panel, an OLED module, and a quantum dot module. It may include a display device. In addition, an electric field including a laptop computer, a television, a computer monitor, an automotive display, or other form of a vehicle, which is a complete product or final product including LCM, OLED module, QD module, etc. A set electronic device such as an equipment display, a mobile electronic device such as a smart phone or an electronic pad, or a set device or set apparatus may also be included.

Accordingly, the display device in the present specification may include a negotiated display device itself such as an LCM, an OLED module, a QD module, etc., and an application product including an LCM, an OLED module, a QD module, etc. .

And, in some cases, the LCM, OLED module, and QD module composed of a display panel and a driving unit are expressed as a "display device" in a narrow sense, and an electronic device as a finished product including the LCM, OLED module, and QD module is "set. It can also be expressed as "device". For example, the display device of consultation includes a display panel of liquid crystal (LCD), organic light emitting (OLED), or quantum dot, and a source PCB that is a control unit for driving the display panel, and the set device is on the source PCB. The concept may further include a set PCB, which is a set control unit that is electrically connected to control the entire set device.

The display panel used in this embodiment is in all forms such as a liquid crystal display panel, an organic light emitting diode (OLED) display panel, a quantum dot (QD) display panel, and an electroluminescent display panel. The display panel of may be used, and is not limited to a specific display panel capable of bezel bending with the flexible substrate for an organic light emitting (OLED) display panel of the present embodiment and the backplay support structure below. In addition, the display panel used in the display device according to the exemplary embodiment of the present specification is not limited to the shape or size of the display panel.

For example, when the display panel is an organic light emitting (OLED) display panel, it may include a plurality of gate lines and data lines, and pixels formed in an intersection area between the gate lines and the data lines. In addition, an array including a thin film transistor, which is an element for selectively applying a voltage to each pixel, an organic light emitting element (OLED) layer on the array, and an encapsulation substrate or an encapsulation layer disposed on the array to cover the organic light emitting element layer. (Encapsulation) and the like may be included. The encapsulation layer may protect the thin film transistor and the organic light emitting device layer from external impact, and prevent moisture or oxygen from penetrating into the organic light emitting device layer. In addition, the layer formed on the array may include an inorganic light emitting layer, for example, a nano-sized material layer or a quantum dot.

In this specification, FIG. 1 illustrates an exemplary organic light emitting (OLED) display panel 100 that may be incorporated into display devices.

1 is a diagram illustrating a plan view of a display panel according to an exemplary embodiment of the present specification. 1 illustrates an exemplary organic light emitting display (OLED) panel 100 that can be incorporated into display devices. Referring to FIG. 1, an organic light emitting display panel 100 includes at least one active layer 101 in which light emitting devices and an array for driving the light emitting devices are formed.

The display panel 100 may include an inactive area IA disposed at the periphery of the active area AA, and the top, bottom, left and right of the active area AA may be referred to as the inactive area IA. The active area AA may have a rectangular shape, and various types of display devices such as a circle, an ellipse, or a polygon may be applied to a smart watch or a display device for a vehicle. Accordingly, the arrangement of the inactive area IA surrounding the active area AA is not limited to the organic electroluminescence (OLED) display panel 100 illustrated in FIG. 1. Various components for driving light-emitting elements and arrays formed in the active area AA are located in the left and right inactive areas IA of the active area AA, thereby providing a function for stable light emission. For example, circuits such as GIP (Gate-in-Panel, 123) and ESD (Electrostatic Discharge, 124), the cathode, which is a part of the light emitting device, and the low potential voltage (VSS), which is the voltage reference point of the light emitting device. Among the areas for contact between the wirings 122 and the encapsulation layer 170 for protecting the light emitting device from external moisture or foreign matter, a plurality of areas for preventing overflowing to the outside of the display panel 100 during the application process of the foreign matter compensation layer There may be a dam structure. In addition, a crack stopper structure for preventing cracks from being transferred into the display panel 100 during a cutting process (scribing process) for dividing the mother substrate into individual display panels 100 126) and the like can be arranged.

The crack prevention structure 126 of the present specification is a GIP 123 or an ESD 124 formed in the inactive region IA, or a low potential voltage ( VSS) It is possible to prevent dark spots from growing or pixel shrinkage by providing a moisture permeation path to the light emitting device or array formed in the active area AA or reaching and destroying the wiring 122. .

The structure of the crack prevention structure 126 may be formed of an inorganic layer or an organic layer, and may be formed of a multilayer structure of an inorganic layer and an organic layer, but is not limited thereto. In FIG. 1, it is illustrated that the crack prevention structure 126 is disposed only on both sides of the long side and one side of the short side of the display panel 100, but is not limited thereto. For example, the crack prevention structure 126 may also be disposed in a region in which the bending region 103 and the notch 151 are formed, and may be disposed on all peripheries of the substrate 110.

In a region adjacent to the cut surface of the substrate 110, which is the outer side of the crack prevention structure 126, a part or the whole of the insulating films (GI, buffer layer, etc.) deposited over the entire surface when the active region AA is formed is etched. can do. A small amount of the insulating film is left on the upper portion of the substrate 110 or the upper surface of the substrate is completely exposed through etching, so that a cutting impact may not be transmitted to the corresponding insulating film.

Referring to FIG. 1, an FPCB electrically connected to a pad 135 formed to receive external power and a data driving signal or to exchange a touch signal may be disposed in a lower area of the display panel 100. High potential voltage (VDD) wiring 121, low potential voltage (VSS) wiring 122 and/or data voltage wiring 127 extending from the FPCB may be disposed.

The data voltage line 127 of the present specification may be connected to and disposed toward a data driver IC (IC) that generates a light emitting signal of the light emitting device 112.

The area in which the pad 135 and the data driver IC (IC) described above are disposed may be a second component forming unit. A portion of the high-potential voltage wiring 121 and the low-potential voltage wiring 122 may be disposed in the second component forming part.

Referring to FIG. 1, in the display panel 100 according to an exemplary embodiment of the present invention, a notch formed by cutting the lower edges of the display panel 100 for bending the bending area BA as indicated by a dotted line. , 151) can be placed.

For example, when performing a cutting process for dividing the parent substrate into individual display panels, the cut surface is cut inside the inactive area IA near the lower edge area of the display panel 100, which is a part of the inactive area IA. The notch 151 may be formed to be adjacent to the high potential voltage (VDD) wiring 121 or the low potential voltage (VSS) wiring 122.

In the notch 151 of the present specification, the notch 151 starts at one end of the flexible substrate 110 and a bending process may be performed in the vicinity of the corresponding region. The bending process is terminated in the vicinity of the data driver IC 137, so that the flexible substrate region including the data driver IC (IC) and the FPCB pad 135 may contact the rear surface of the flexible substrate 110 on which the active region AA is formed. .

The member connected to the pad 135 formed on the upper surface of the display panel 100 is not limited to the FPCB, and various members can be connected, and the position of the pad 135 may be disposed on the upper surface or the rear surface of the display panel 100 Do.

In FIG. 1, the data driver IC (IC) is illustrated as being disposed on the upper surface of the display panel 100, but is not limited to the data driver IC (IC), and the location of the data driver IC (IC) is also on the upper surface of the display panel 100. It is not limited and can be placed on the back side.

FIG. 2 is a cross-sectional view taken along a cut line I-I' shown in FIG. 1 for emphasizing a cross-section of the inactive area IA of the display panel 100 of FIG. 1 in a bent state. In FIG. 2, the active layer 101 is illustrated to include a flexible substrate 110 and a TFT, a light emitting device, and an encapsulation layer 170 that may be formed on the flexible substrate 110.

The flexible substrate 110 may be, for example, a polyimide resin-based material, but is not limited thereto. A buffer layer 111 may be formed on the flexible substrate 110 and an active layer 101 may be formed. The buffer layer 111 may have a structure in which a plurality of inorganic insulating layers such as SiNx or SiOx are stacked, but is not limited thereto. The active layer 101 may be formed of low temperature poly silicon (LTPS), and a gate insulating layer 120 may be disposed on the active layer 101. A gate layer GE may be formed on the gate insulating layer 120, and the gate layer GE may be formed of molybdenum (Mo). An interlayer insulating layer 130 may be formed on the gate layer GE, and holes are formed in the gate insulating layer 120 and the interlayer insulating layer 130 to form a source electrode SE and a drain electrode DE of the TFT as an active layer. You can connect with (101). A first planarization layer 150 and a second planarization layer 160 may be disposed on the source electrode SE and the drain electrode DE. The planarization layer may be formed of an organic layer. An anode electrode AD, an organic emission layer EL for light emission, and a cathode electrode CD may be formed on the second planarization layer 160.

An encapsulation layer may be formed on the cathode electrode CD to protect the organic emission layer EL from external moisture or foreign matter. The encapsulation layer 170 may have a three-layer structure of an inorganic film/organic film/inorganic film, and the inorganic film may be a Si-based SiNx, SiOx, or SiON.

The organic layer applied to the encapsulation layer 170 may be a particle capping layer (PCL), and is not limited to terms. The particle cover layer may be formed of a material such as epoxy resin, which is a polymer. In the case of the inorganic film, an inorganic material composed of a plurality of layers such as SiNx/SiON may be used instead of a single layer. Each inorganic layer may be formed to a thickness of about 0.5 to 1 μm, and an organic layer may be formed to a thickness of about 7 to 20 μm, but the thickness of the inorganic layer and the organic layer is not limited to the embodiment.

The above-described buffer layer 111 to the encapsulation layer 170 may be referred to as the active layer 101.

A bending area 103 is disposed in the inactive area IA, which is an area surrounding the active layer 101, and various types of bending areas 103 are disposed above the substrate 110 corresponding to the bending area 103. A micro coating layer (MCL, 360) may be disposed to prevent cutting and damage of the wires.

The micro-coating layer 360 is disposed on various wires, such as a data wire 127, a high-potential voltage wire 121, and a low-potential voltage wire 122 formed on the bending area 103, The position can be adjusted to be closer to the Neutral Line. Accordingly, the tensile stress formed on the neutral line and the contractile stress formed on the neutral line are applied as small as possible to the wirings, thereby improving the durability of the wiring. In addition, the micro-coating layer 360 may also include physical and chemical protection functions capable of protecting various wires disposed on the flexible substrate 110 from external impacts, moisture, or dust during the manufacturing process.

FIG. 3 is an enlarged view of an area in which the notch 151 of FIG. 1 is disposed, and shows components of the bending area BA and the inactive area IA before performing the bending process.

The notch 151 may be generated by cutting the edge of the flexible substrate 110 at a position corresponding to the bending area BA folded to the rear surface of the substrate 110 when bending in the inactive area IA. The substrate cutting line as shown in FIG. 3 may be formed by a substrate cutting method using a laser. In the case of a slim bezel or a narrow bezel, the smaller the area of the substrate 110 to be bent during the bending process, the smaller the stress applied to the substrate 110 during bending, and thus processability may be further improved. In addition, a crack prevention structure 126 may be formed inside the substrate 110 along the cut surface including the notch 151 to prevent propagation of cracks that may occur during the cutting process. As shown in FIG. 3, the cut surface of the substrate 110 has rounded corners, thereby improving fairness and durability.

The GIP 123 and the ESD 124 may be disposed on the side of the active area AA, and the low-potential voltage wiring 122 for grounding may be disposed along the periphery. External power coming from the pad 135 passes through the bending area BA through the high potential voltage line 121, the data line 127, and the gate power line 125, and the inactive area close to the active area AA ( IA). In addition, the data line 127 may extend from the driver IC IC to pass through the bending area BA and enter the active area AA. By configuring various wires to pass through the bending area BA, most of the wires may be exposed to tensile stress and contraction stress during the bending process. When the bending area (BA) is bent with a radius curvature (R) smaller than the design value that the wirings passing through the bending area (BA) can withstand, stress is concentrated in the part corresponding to the radius of curvature smaller than the design value of the wiring. May cause damage to the wiring. As a result, a defect in which the display panel 100 does not operate properly may occur.

Accordingly, it may be important to prevent the flexible substrate 110 from being deformed due to an additional external force with a constant radius of curvature R in order to protect the wirings of the bending area BA.

4 is a cross-sectional view showing a structure of the display panel 100 when bending is completed. For convenience of illustration, the TFT array and the light emitting device formed on the flexible substrate 110 in FIG. 4 are indicated as a flat active layer 101, and the encapsulation layer 170 is the upper surface of the active layer 101 and the bending area ( It may be a triple layer of an inorganic film/organic film/inorganic film covering the side of the BA) side, but the illustration is omitted in FIG. 4. The configuration of the encapsulation layer is not limited thereto.

A touch electrode layer 181 capable of recognizing a touch and a first adhesive layer may be disposed on the active layer 101. The touch electrode layer 181 may be, for example, an electrostatic touch method capable of sensing a touch pressure, a force touch method, or an example of a pen touch method using a pen, but is not limited thereto.

A polarizing layer 182 may be disposed on the touch electrode layer 181 according to the exemplary embodiment of the present specification. The polarization layer 182 may minimize an effect that light generated from an external light source may enter the display panel 100 and have an effect on the active layer 101. The embodiment of the present specification is not limited to the structure of FIG. 4. For example, in the case of a product sensitive to touch sensitivity, the order of the touch electrode layer 181 and the polarizing layer 182 may be changed and disposed.

According to the exemplary embodiment of the present specification, the second adhesive layer 183 may be disposed on the polarizing layer 182. The cover window 190 may be attached to the outside of the display panel 100 to protect the display panel 100 from an external environment. The cover window 190 may be a cover glass, a cover member, or the like, and is not limited to terms.

A support layer 116 may be disposed under the flexible substrate 110, and a second touch electrode layer may be disposed under the support layer 116. The support layer 116 may be made of, for example, polyethylene terephthalate (PET), but is not limited thereto. In the second touch electrode layer, a second sensor layer for force touch sensing a touch pressure or an electromagnetic sensing method touch sensing touch with a pen may be disposed under the flexible substrate 110.

A layer formed of metal may be additionally disposed under the support layer 116 or under the second touch electrode layer. Noise may occur in the battery or semiconductor chips of the module to which the display panel 100 is attached, and electromagnetic interference (EMI) may occur in the display panel 100 due to noise. I can. Electromagnetic interference may cause a malfunction in the thin film transistor of the active layer 101 or the organic light-emitting device (OLED) or an abnormality in the display screen of the display panel. In order to prevent this, for example, by disposing a metal layer having a thickness of about 0.1 mm, electromagnetic interference (EMI) can be blocked. Alternatively, by disposing the metal layer, a heat dissipation effect of dispersing heat generated from a light source of the display panel 100 and a rigidity effect of supporting the flexible substrate 110 may be obtained.

An adhesive layer 118 may be disposed between the bent flexible substrate 110. The adhesive layer 118 may be disposed under the support layer 116 to maintain the bent shape. For example, the adhesive layer 118 may be a double-sided adhesive layer. For example, the double-sided adhesive layer may comprise foam tape, pressure sensitive adhesive, foam-type adhesive, liquid adhesive, light curing adhesive or any other suitable adhesive component. The adhesive layer 118 may be formed of or include a compressive material, and the compressive material may be a cushion for portions bonded to the adhesive layer 118. For example, the constituent material of the adhesive layer 118 may be compressible. The adhesive layer 118 may be composed of a plurality of layers including a cushion layer, for example polyolefin foam, interposed between an upper layer and a lower layer of an adhesive material. The adhesive layer 118 may be disposed on at least one of an upper surface and a lower surface of the extended body portion of the support layer 116.

The FPCB is formed on the upper surface of the flexible substrate 110, but is bent to be electrically connected to the driver IC (IC), the pad 135 and the pad 135, and may be disposed on the opposite side of the active layer 101.

A micro-coating layer 360 may be disposed to protect wiring or the like on the flexible substrate 110. For example, the micro-coating layer 360 is a bending area BA to contact the lower surface of the touch electrode layer 181 including the upper surface of the active layer 101 starting from the vicinity of the driver IC (IC) for sufficient protection of the wiring. Can be configured throughout. A portion of the micro-coating layer 360 may be over-coated at the end of application, or may be disposed to be in contact with or adjacent to the side surface of the touch electrode layer 181 due to a surface tension between the touch electrode layer 181 and the micro-coating layer 360. The micro-coating layer 360 may be formed over the entire area from the adjacent area of the driver IC (IC) to the active layer 101 through the bending area BA. As described in FIG. 1, the inactive area IA and the It may be disposed along the line of the notch 151 formed over the bending area BA.

When the flexible substrate 110 on which the micro-coating layer 360 is disposed is bent, a bending portion (BP) may be arbitrarily designated on the upper portion of the flexible substrate 110 according to the position as shown in FIG. 4. The bending portion may vary according to the radius of curvature R of the flexible substrate 110 when bending is performed. For example, in the active area AA or the pad 135 to which the FPCB is attached, the point where the bending area BA starts may have the largest radius of curvature R1, and the first bending portion BP1 and the fifth bending It may be referred to as a portion BP5, which may have a radius of curvature R2 smaller than a radius of curvature R1 toward the center of the bending area BA, and may be referred to as a second bending portion BP2 and a fourth bending portion BP4, respectively. The central portion of the bending area BA may have the smallest radius of curvature R3, and may be referred to as the third bending portion BP3.

As the radius of curvature for each bending area of the flexible substrate 110 varies, the compressive stress and tensile stress applied for each section may be different. For example, the third bending portion BP3 having the smallest radius of curvature R3 has a much greater compressive stress and tensile stress than the first bending portion BP1 or the fifth bending portion BP5 having the largest radius of curvature R1. Can be authorized. The difference in compressive stress and tensile stress for each bending portion BP may be that the compressive stress and tensile stress applied to the wiring on the flexible substrate 110 are different. The wiring of the third bending portion BP3 to which the largest compressive stress and tensile stress is applied and the wiring of the first bending portion BP1 to which the lowest compressive stress and tensile stress are applied may be configured differently.

5 is a plan view of the first bending portion BP1 of FIG. 4. The first bending portion BP1 disclosed in FIG. 5 includes various wirings such as a high potential voltage (VDD) wiring, a low potential voltage (VSS) wiring, and a data signal line extending from the active area AA. It represents a plane arranged in the first direction at the midpoint of the bending area BA. On the left side of FIG. 5, there may be a notch 151 in the trimming line obtained by cutting the flexible substrate 110. A crack prevention structure 126 may be disposed so that cracks that may occur during the laser cutting process for forming the notch 151 cannot be transmitted to the wiring formation section.

Among the wirings extending from the active area AA, an arbitrary wiring disposed in the inactive area IA is used as the inactive wiring 300, and the wiring extending to the bending area BA is bent with the lower wiring 310 It may be referred to as the upper wiring 320. The inactive wiring 300 and the bending lower wiring 310 may be the same wiring. A connection part CNT to which the bending lower wiring 310 and the bending upper wiring 320 are connected may be disposed between the inactive wiring 300 and the bending lower wiring 310. For example, the bending lower wiring 310 and the bending upper wiring 320 may be electrically connected through the connection part CNT. The connection part CNT may be disposed in the inactive area IA to form an electrical and mechanical connection structure between the bending lower wiring 310 and the bending upper wiring 320 before the bending area BA starts.

In the active area AA and the inactive area IA, wiring may have a line shape. The wiring in the bending area BA may have an elliptical chain shape, a rhombic chain shape, a zigzag shape, etc. to withstand compressive stress and tensile stress. In the examples of the present specification, an elliptical chain is used as an example, and the present disclosure is not limited thereto.

6 is a plan view of the second bending portion BP2 of FIG. 4. The second bending portion BP2 disclosed in FIG. 6 represents a planar shape that has moved from the first bending portion BP1 of FIG. 5 to the bending area BA. The bending lower wiring 310 and the bending upper wiring 320 may be arranged in the first direction at regular intervals. As shown in FIG. 5, a notch 151 and a crack prevention structure 126 disposed inside may be disposed. Since the second bending portion BP2 has a smaller radius of curvature than the first bending portion BP1, the bending lower wiring 310 and the bending upper wiring 320 are electrically and mechanically connected to each other at regular intervals. A connection part (CNT) may be formed. The bending lower wiring 310 and the bending upper wiring 320 are disposed on the same plane layer as the connection part CNT. For example, the bending lower wiring 310 and the bending upper wiring 320 may be disposed on the same plane layer to connect the two wirings. A distance L1 between the connection part CNT and the next connection part CNT in one wire disposed on the second bending part BP2 may be uniformly disposed. The arranged connection portion CNT may be formed in a circular structure having a constant width W1. The shape of the connection part CNT is not limited to a circular shape. The connection portion CNT may partially form a region in which the line width of the wiring is increased, and thus may serve to withstand the compressive stress and tensile stress applied in the first direction. If the connection part CNT having a certain width W1 with a certain distance L1 is arranged at the same position as the connection part CNT of an adjacent wiring, overlap may occur between adjacent connection parts CNT in the narrow bending area BA. . In order to solve this problem, the connection portion CNT of the adjacent wiring may be shifted upward and downward based on the first direction, which is the wiring extension direction. Through the shift of the connection part (CNT), it is possible to arrange the connection part (CNT) having a width greater than that of the bending lower wire 310 and the upper bending wire 320 while maintaining a minimum distance as shown in FIG. 6 without interference. have.

7 is a plan view of the third bending portion BP3 of FIG. 4. As shown in FIG. 6, the notch 151 and the crack prevention structure 126 may be disposed outside and wires may be disposed in the inner bending area BA. The third bending portion BP3 has the smallest radius of curvature in the bending area BA, and may have the greatest compressive stress and tensile stress applied to the lower bending wiring 310 and the upper bending wiring 320. In order to overcome such compressive stress and tensile stress, wirings of the third bending portion BP3 may have a size of the connection portion CNT larger than that of the second bending portion BP2. Since the width W2 of the connection part CNT is larger, the connection part CNT where the bending lower wiring 310 and the bending upper wiring 320 meet may more stably maintain physical contact. In addition, in order to increase the number of the connection portions CNTs arranged, the distance L2 between the first-direction reference connection portion CNT and the connection portion CNT of the wiring may be made narrower than that of the second bending portion BP2. The connection portion CNT may partially withstand the compressive stress and tensile stress applied in the first direction by forming a region in which the width of the wiring is increased. Since more connection parts (CNT) are arranged in the third bending part (BP3) than in the second bending part (BP2), the lower bending wire 310 and the upper bending wire 320 can withstand stronger compressive stress and tensile stress. have. The bending lower wiring 310 and the bending upper wiring 320 are disposed on the same plane layer as the connection part CNT. For example, the bending lower wiring 310 and the bending upper wiring 320 may be disposed on the same plane layer to connect the two wirings.

FIG. 8 is a cross-sectional view of a section III-III' in which the bending lower wiring 310 and the bending upper wiring 320 of FIG. 6 are electrically and physically connected by a connection part (CNT). The bending lower wiring 310 may be disposed on the flexible substrate 110, and the first planarization layer 150 of the active layer 101 may be disposed between the bending lower wiring 310 and the bending upper wiring 320. In the plan view of FIG. 6, a hole of the first planarization layer 150 may be formed at a location where the connection portion CNT is formed. A connection part CNT through which the bending lower wiring 310 and the bending upper wiring 320 make electrical and physical contact may be formed through the hole. The connection part CNT may have a constant width W1. The second planarization layer 160 may be disposed on the bent upper wiring 320, and the micro-coating layer 360 described in FIG. 2 may be formed. When the bending area BA is bent due to the micro-coating layer 360, the bending lower wiring 310 and the bending upper wiring 320 may be configured to be disposed on a neutral surface.

9 is a cross-sectional view of a section IV-IV' in which the bent lower wiring 310 and the bent upper wiring 320 of FIG. 7 are electrically and physically connected through a connection part CNT. As described in FIG. 8, a bending lower wiring 310, a first flattening layer 150, a bending upper wiring 320, a second flattening layer 160, and a micro-coating layer 360 on the flexible substrate 110 Can be placed. A connection part (CNT) in which a hole is formed in the first planarization layer 150 between the bending lower wiring 310 and the bending upper wiring 320 so that the bending lower wiring 310 and the bending upper wiring 320 are in electrical and physical contact. ) Can be formed. The connection part CNT may have a certain width W2. Compared to the width W1 of the connection part CNT of FIG. 8 showing the cross-section of the second bending part BP2, the width W2 of the connection part CNT may be larger in the cross-section of the third bending part BP3. have. The width W2 of the connection portion CNT of the third bending portion BP3 may be formed to be about 6 to 8 μm, but is not limited thereto. When the flexible substrate 110 is bent in the first direction, the magnitude of the compressive stress and tensile stress applied in the first direction to the bending lower wiring 310 and the bending upper wiring 320 disposed on the flexible substrate 110 The third bending portion BP3 may be larger than the second bending portion BP2. By arranging a connection part (CNT) having a larger width W2 in the third bending part BP3, the compressive stress and tensile stress applied to the third bending part BP3 are applied to the bending lower wiring 310 and the bending upper wiring 320. ) Can be tolerated.

10 is a diagram showing a cross-sectional structure of the bending area BA. The flexible substrate 110 may be disposed to have a curvature in the lowermost layer of the display device, and the lower bending wiring 310 and the upper bending wiring 320 may be disposed on the flexible substrate 110. The first flattening layer 150 is disposed between the bending lower wiring 310 and the bending upper wiring 320, and the second flattening layer 160 and the micro-coating layer 360 are disposed on the bending upper wiring 320. I can. As can be seen from the cross-sectional structure of the bending lower wiring 310 and the bending upper wiring 320, by arranging the wiring of the bending area BA in a double structure and arranging a plurality of connection portions (CNTs) in the wiring extension path, the wirings Even if a crack occurs due to compressive stress and tensile stress in any one of the parts, a bypass path for data or power can be secured. In addition, since the connection portion (CNT) is disposed between the bending lower wiring 310 and the bending upper wiring 320, a wiring structure that is stronger against compressive stress and tensile stress can be made.

A display device according to an exemplary embodiment of the present specification includes a liquid crystal display device (LCD), a field emission display device (FED), an organic light emitting display device (OLED), It includes a quantum dot display device.

The display device according to the exemplary embodiment of the present specification includes a notebook computer, a television, a computer monitor, an automotive display device, or another vehicle that is a complete product or a final product including an LCM, an OLED module, and the like. It may also include a set electronic device apparatus or a set device such as an equipment display apparatus, a mobile electronic device such as a smartphone or an electronic pad, etc. I can.

A display device according to an exemplary embodiment of the present specification may be described as follows.

The display device according to the exemplary embodiment of the present specification includes an active area and an inactive area, and the inactive area includes a first area adjacent to the active area, a second area in which a pad is disposed, and between the first area and the second area. There is a flexible substrate including a bending area in which there is a bending area, and the bending area includes the first bending point, the second bending point, and the third bending point according to the radius of curvature, and the radius of curvature of the first bending point is less than that of the third bending point. It can be big.

In the display device according to the exemplary embodiment of the present specification, the bending region further includes a bending lower wiring, a first organic insulating layer, and a bending upper wiring, and the bending upper wiring and the bending lower wiring are electrically connected through the opening of the first organic insulating layer. There is a connection part.

A display device according to an exemplary embodiment of the present specification includes a first connector and a second connector disposed at a second bending point, and a third connector and a fourth connector disposed at the third bending point.

A display device according to an exemplary embodiment of the present specification includes a bending area disposed at the second bending point, a lower bending line and an upper bending line electrically connected, and including a first connection part and a second connection part disposed on the same line. , The bending area is electrically connected to the lower bending wiring and the upper bending wiring arranged at the third bending point, and may include a third connection portion and a fourth connection portion arranged on the same line.

In the display device according to the exemplary embodiment of the present specification, a distance between the first connector and the second connector may be greater than a distance between the third connector and the fourth connector.

In the display device according to the exemplary embodiment of the present specification, the first connector may have a smaller area than the third connector.

In the display device according to the exemplary embodiment of the present specification, the line width of the first wiring line may be smaller than the width of the first connector.

In the display device according to the exemplary embodiment of the present specification, the lower bending line and the upper bending line disposed at the second bending point and the third bending point disposed in the bending area may overlap with the first organic insulating layer interposed therebetween.

The display device according to the exemplary embodiment of the present specification may further include a lower bending line and a crack prevention structure adjacent to the upper bending line.

The display device according to the exemplary embodiment of the present specification may further include a second organic insulating layer and a micro-coating layer on the bending upper wiring and the crack prevention structure.

A display device according to an exemplary embodiment of the present specification includes a substrate including a display area and a non-display area, a light-emitting display device disposed in the display area, and an encapsulation layer disposed on the light-emitting display device and disposed on at least a portion of the non-display area And a polarizing layer and a cover window disposed above the encapsulation layer, and the non-display area includes a bending area, the bending area includes a first wiring line and a second wiring line directed to the light emitting display device, and a first wiring line The and the second wiring lines may have a connection portion that overlaps in the bending area and electrically connects the first wiring line and the second wiring line.

In the display device according to the exemplary embodiment of the present specification, the connection portion may be arranged in a circular plane.

In the display device according to the exemplary embodiment of the present specification, the bending area includes a first bending point having a first radius of curvature and a third bending point having a third radius of curvature, and the first radius of curvature is larger than the third radius of curvature. I can.

In the display device according to the exemplary embodiment of the present specification, the second bending point may include a first connector, the third bending point may include a second connector, and a width of the first connector may be smaller than a width of the second connector.

In the display device according to the exemplary embodiment of the present specification, the first bending point includes a first connecting portion and a second connecting portion disposed on the same line, and the third bending point is a third connecting portion and a fourth connecting portion disposed on the same line. And a distance between the first connection part and the second connection part may be greater than a distance between the third connection part and the fourth connection part.

In the display device according to the exemplary embodiment of the present specification, the cross-sectional width of the first wiring line may be smaller than the cross-sectional width of the connection portion.

In the display device according to the exemplary embodiment of the present specification, a first organic insulating layer may be disposed between the first wiring line and the second wiring line, and a second organic insulating layer and a micro-coating layer may be disposed on the second wiring line.

The display device according to the exemplary embodiment of the present specification includes at least one crack prevention structure adjacent to the first wiring line and the second wiring line disposed on the outermost side of the bending area.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and are not restrictive. The scope of protection of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: display panel
101: active layer
AA: Active area IA: Inactive area
BA: bending area
110: substrate 111: multi buffer layer
120: gate insulating film 130: first interlayer insulating film
140: second interlayer insulating film
150: first planarization layer 160: second planarization layer
170: encapsulation layer
121: high potential voltage wiring (Vdd) 122: low potential voltage wiring (Vss)
123: GIP 124: ESD
125: gate power line
126: Crack Stopper Structure
127: data wiring
116: support layer 118: double-sided adhesive layer
181: first adhesive layer and touch film 182: polarizing film
183: second adhesive layer
190: cover glass
360: Micro Coating layer (MCL)
134: Foam Tape
135: pad 136: flexible printed circuit board (FPCB)
IC: Driver IC
151: cutting plane
CNT: connection

Claims (18)

Including an active area and an inactive area, wherein the inactive area includes a first area adjacent to the active area, a second area in which a pad is disposed, and a bending area between the first area and the second area A flexible substrate;
The bending area includes a first bending portion, a second bending portion, and a third bending portion according to a radius of curvature;
The flexible display device, wherein a radius of curvature of the first bending portion is larger than a radius of curvature of the third bending portion. The method of claim 1,
The bending region further includes a bending lower wiring, a first insulating layer, and a bending upper wiring,
The flexible display device, wherein the bending upper wiring and the bending lower wiring include a connection part connected through an opening of the first insulating layer. The method of claim 2,
A first connecting portion and a second connecting portion disposed on the second bending portion; And
The flexible display device comprising: a third connection portion and a fourth connection portion disposed on the third bending portion. The method of claim 1,
The bending area further includes a bending lower wiring and a bending upper wiring,
It is disposed on the second bending portion, the lower bending wiring and the upper bending wiring are connected, including a first connecting portion and a second connecting portion disposed on the same layer,
The flexible display device comprising: a third connector and a fourth connector disposed on the same layer and connected to the lower bending line and the upper bending line disposed on the third bending portion. The method of claim 4,
The flexible display device, wherein a distance between the first connection part and the second connection part is greater than a distance between the third connection part and the fourth connection part. The method of claim 4,
The flexible display device, wherein an area of the first connector is smaller than an area of the third connector. The method of claim 3,
The flexible display device, wherein a width of the bent lower wiring is smaller than a width of the first connector. The method of claim 2,
The flexible display device, wherein the bending lower wiring and the bending upper wiring disposed on the second bending portion and the third bending portion overlap with the first insulating layer therebetween. The method of claim 2,
The flexible display device further comprising: a crack prevention structure adjacent to the lower bending wiring and the upper bending wiring disposed at the outermost side of the bending area. The method of claim 9,
The flexible display device further comprising a second insulating layer and a micro-coating layer on the bending upper wiring and the crack prevention structure. A substrate including a display area and a non-display area including a bending area;
A light-emitting display device disposed in the display area and an encapsulation layer disposed on the light-emitting display device and disposed on at least a portion of the non-display area; And
It includes a polarizing layer and a cover window disposed on the encapsulation layer,
The bending area includes a first wiring and a second wiring directed to the light emitting display device;
The flexible display device, wherein the first wiring and the second wiring overlap in the bending area and have a connection portion to which the first wiring and the second wiring are connected. The method of claim 11,
The flexible display device, wherein the connection part has a circular planar shape. The method of claim 11,
The bending area includes a second bending portion having a second radius of curvature and a third bending portion having a third radius of curvature, and the second radius of curvature is larger than the third radius of curvature. The method of claim 13,
The second bending portion includes a first connection portion,
The third bending portion includes a third connecting portion,
The flexible display device, wherein a width of the first connection part is smaller than a width of the third connection part. The method of claim 13,
The second bending portion further includes a first connecting portion and a second connecting portion disposed on the same layer,
The third bending portion further includes a third connection portion and a fourth connection portion disposed on the same layer,
The flexible display device, wherein a distance between the first connection part and the second connection part is greater than a distance between the third connection part and the fourth connection part. The method of claim 11,
The flexible display device, wherein a width of the first wiring is smaller than a cross-sectional width of the connection portion. The method of claim 11,
Further comprising a first insulating film disposed between the first wiring and the second wiring,
The flexible display device further comprising a second insulating layer and a micro-coating layer disposed on the second wiring. The method of claim 17,
The flexible display device comprising: at least one crack prevention structure disposed adjacent to the first wire and the second wire disposed on the outermost side of the bending area.

Images